Have you had a chance to hear it or are you just looking at the measurements?

Don't know if Jason has heard it. Mike Moffat has heard it with the Yggy and pretty darn good (for the $$) turntable rig.

Casey at LHLabs and Jazmin at UE have also heard it. She's not an audio forum troll though, but her reaction was priceless. Wish I had that on video.

Have you had a chance to hear it or are you just looking at the measurements?

It's simply a matter of "holy cow" measurements for a transformer coupled amp. Both the Tribute interstages and Cinemag OPTs are mighty impressive as far as performance at the low extreme. Most transformers can't even hit 20Hz flat, much less have inaudible or near inaudible distortion. To be fair, there is 1.45db feedback from the tertiary windings of the Cinemags. That does tend to help extension and distortion.

Are these measurements the end all be all? Of course not. Do I personally hear perfection in the bass? Almost. 90% there. Nothing is perfect. Still the best bass quality from a tube amp I've ever heard - subjectively exceeding that of many solid-state amps.

See FR below. Using FFT averaged white noise, so a big jaggy. FFT size of 65536 pts might limit measurement of low bass, but we still got some idea. Graph goes down to 1Hz. 100 ohm load. Amps go in this order:

The Studio
Vali
Magni 2


Magni wins again. But The Studio reaches down to 20Hz clean with -1db at 16Hz.

It's simply a matter of "holy cow" measurements for a transformer coupled amp.

This. The Studio's distortion performance is *very* good. The slight odd-order distortion at the bottom of the response might add a small bit of character there, but it might help keep the bass from going limp as the volume goes up.

The only thing that looks funny compared to the other graphs...

The only thing that looks funny to me are the uneven sidebands in the Studio's IM plots, which imply a level of phase-intermodulation-distortion that is within spitting distance of the (amplitude)IM itself. I'm not suggesting it is audible, just notable.

It's simply a matter of "holy cow" measurements for a transformer coupled amp. Both the Tribute interstages and Cinemag OPTs are mighty impressive as far as performance at the low extreme. Most transformers can't even hit 20Hz flat, much less have inaudible or near inaudible distortion.

Exactly. After testing some passive transformer-based summing solutions for transforming a circlotron's balanced output to single-ended, I have immense respect for any transformer that can (a) do anything at all at 20 Hz, and (b) meet or exceed its stated distortion performance at low frequencies. You're talking $$$$$$$ iron to do that.

And nope, I haven't heard the Studio yet. I'm a little scared to. I think, at heart, I really do enjoy doing the most we can at the lowest cost. Oddly enough (considering his history), so does Mike.